P2345
Cylinder 10 Above Knock/Combustion Vibration Sensor Threshold
Ignition / knock control
Generic OBD-II
Medium
What it means
P2345 means the knock (combustion-vibration) sensor detected vibration above the allowed threshold on cylinder 10, indicating detonation or a sensor fault. The ECM typically retards timing, cutting power slightly. Common causes are low-octane fuel, carbon buildup, overheating, or a faulty knock sensor.
Medium
Can I keep driving? Drivable, but the ECM may pull timing and reduce power; ongoing detonation can damage the engine, so use good fuel and fix the cause.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power as ignition timing is retarded
- Audible knock or ping under load
- Slightly reduced fuel economy
Common causes
Most likely first
- Genuine detonation on cylinder 10 — low-octane fuel, carbon buildup, or overheatingLikely
- Lean condition or excess intake air on that cylinderCommon
- Faulty knock/combustion-vibration sensorCommon
- Knock sensor wiring or connector faultLess often
- ECM misreading the sensor signal (less common)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for overheating, lean trims, or related codes.
- Try a tank of correct-octane, top-tier fuel to rule out bad fuel.
- Inspect the knock sensor connector and wiring.
- Check for causes of detonation — cooling system, carbon deposits, EGR flow.
- Test or replace the knock sensor if the mechanical side is healthy, then re-test.
FAQ
Quick answers
Is it safe to drive with P2345?+
Light driving is usually fine because the ECM retards timing to protect the engine, but persistent knock can cause real damage. Address the cause soon.
Can I just clear P2345?+
It returns if the knock continues. Fix the fuel, cooling, or sensor issue behind it first.
Related codes
Often seen with P2345
Read & clear P2345 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX